Optical whitening agents



(in which R represents an amino group, or a residue of United States Patent l i l 2 cordingly the invention comprises such compounds to- 2, 75,10 getger witlhlsalts tlhereof, especially1 water-soluble salts suc as al a i-meta e. g. sodium sa ts; Q1 TICAL WHITENING AGENTS The primary or secondary amines from which the groups Dennis Arthur William Adams, Leeds, and Asim Kumar R and R are derived include for example aliphatic amines Samar, C fl fo England, aSsignm-s t Hi k & oflow molecular weight such as methylarnnne, ethylamine, Welch Limited, Castleford, England, a British company propylamine, butylamine, dimethylamine, dipropylamine, monoethanolamine, diethanolamine and we prefer the No Drawing :Apphcatmn March 1957 group R to be a residue of one of these amines. Other Sena} 646227 10 suitable amines include aryl amines for example, aniline, an anisidine or a toluidine, which may if desired contain substituents such as halogen, alkyl oralkoxy groups; solubilizing groups such as sulphonic and carboxylic groups may also be persent but the presence of a chromophoric group such as a nitro group is undesirable. Heterocyclic aminessuch as morpholine are also suitable. We prefer the group R to be a residue of one of the aryl or heterocyclic amines mentioned above. a

a As will be appreciated the groups R and R are symmetrically placed in the compounds of formula l above, these groups being in the 3- and 5positions relative to the side chain. Therefore, in the preparation of such compounds, Which is described hereafter, it will be apparent that the groups R and R may be attached in any desired sequence. t t

The compounds of the present invention have a good aflinity for cellulosic materials, particularly cotton and Optical whitening agents in general absorb light in the linen textiles and paper, and exhibit a green fluorescence. ultra violet range of the spectrum and emit in the visible They have only a moderate or balanced substantivity to spectrum, usually in the bluish green to bluish violet. cellulosic material and thus, when used as optical whit- Thus, the fluorescence of such compounds in white maening agents in washing preparations they do not build terial tends to counteract any yellowing as for example up in the material being treated to the same extent as that resulting upon repeated washing of a white cotton or known optical whitening agents. They may conveniently linen textile. The compounds used as optical whitening be used in conjunction with other known optical whitagents must be substantive to the material being treated, ening agents which exhibit a bluish or violet fluorescence, and must be substantially stable when dyed on the mafor example certain stilbene derivatives, in which case the terial being treated. buildup of the unpleasant reddish-tinged fluorescence, re- A disadvantage which results however from the use of ferred to above can be substantially reduced. A control many of the known optical whitening agents such as cerof the optical whitening produced in a textile can theretain derivatives of stilbene, which fluoresce in the blue or fore be achieved by the use of a composition containing a blue-violet end of the visible spectrum, is that they have compound according to the invention together with known optical whitening agents.

too high an afiinity for cellulose and consequently a textile According to a feature of the invention therefore there after repeated treatment may take on an unpleasant reddish tinged fluorescence due to build-up of the optical is provided a composition adapted for the treatment of Claims priority, application Great Britain March 21, 1956 16 (Zlaims. (Cl. 117335) This invention is concerned with improvements in or relating to optical whitening agents and is more particularly concerned with certain new compounds for use as optical whitening agents.

Optical whitening agents have in recent years found extensive use in the treatment of textiles particularly during washing and are designed to counteract the yellow or off-white colour which white textiles, particularly cellulosic textiles, may possess, especially after repeated washing. Such optical whitening agents also tend to improve coloured textiles as they impart a general brightness to them. They are also widely used to impart whiteness to other cellulosic material, particularly paper.

whitening agent on the textile. cellulosic materials comprising a compound of the for- It is an object of the present invention to provide optical mula 1111 1 c t w Pi -h C--NH- OH=OHONHC CONE-41 i-R whitening agents for cellulosic materials in which the or a salt thereof, preferably water soluble salts, especially above-mentioned disadvantage is reduced.

We have found that certain new compounds of the the above stated meanings) which composition may, if general formula:

desired, contain other optical whitening agents. The invention also includes in particular cotton or linen texa primary or secondary amine which does not contain an tiles, and paper, when treated with such a composition.

auxochrome or a chromophore, which is linked to the ad- Compositions containing the new optical whitening jacent triazine ring through its nitrogen atom, and R agents may take any convenient form, for example the represents a chlorine atom, a hydroxyl group or has the optical whitening agents may be incorporated in detersame meaning as R and salts of such compounds can gents a or soaps for washing textiles, the detergents or be used with advantage as optical whitening agents. Acsoaps being in solid or liquid form. The new optical alkali metal e. g. sodium salts (where R and R have.

7 2,876,106 3 4 whitening agents may: also be incorporated in baths for starting material for the reduction may conveniently be the treatment of cellulosic materials during their producprepared by the condensation of p-nitrobenzoyl chloride tion or for treatment of the finished textile article. with 4-amino-4-nitro-stilbene-2:2-disulphonic acid.

The optical whitening agents may also be incorporated In order that the invention may be well understood in compositions for the treatment of paper and photo 6 the following examples are given by way of illustration graphic paper where high whiteness isnecessary. only (in these examples, the composition of the final The new compounds according to the invention may product is stated by specifying the groups R and R in conveniently beprepared by reacting a compound of the the general Formula I given above; also parts are parts formula by weight): 7

11 or i i i n 01-0 C-NH- CH=CHONH.OONHC' C-Gl v N N SO H S0311 II withone or more compounds of the general formula HX 20 Example 1 m Whlch X represents an ammo group or a resldue of A solution of 165 parts of 4-nitro-4'-amino-stilbenea primary or secondary amine which does'not contain disul I phonic acid (80% strength), neutralised with f ailxochmme lmked' to the hydrogen atom thlough 35 parts of sodium carbonate, in 1200 parts of water, is us nitrogen atom to effectreplacement i or i heatedto 70 C; To this'solution is' added dropwise with g i group 5 i 2 g? 25 vigorous stirring, a solution of 67 parts of p-nitro-benzoyl a oms, 1 eslre su sequen y elng r p ace chloride in 200 parts of toluene during half-an-hour with droxyl groups.

The number of chlorine atoms replaced by the group 321 53 2 ggfgg figgg fg i 36 parts of calcium car X will depend largely on the conditions used for the re- Th e stlrred mixture is heated gently to the boiling $5 and the 3 ram tbs if h 30 point and refluxed for about 2' hours. It is then acidified p acement reactions are convemently carried out in with hydrochloric acid and cooled to C The Solution at neutrill the replacement of the first two cipitated solid is filtered and washed. The product 4- chlfmnehatoms m genera} takmg place at 50 amino 4 (p nitrobenzoyl-amino)-stilbene-2:2-disulwhflit t e .replacement of further chlorme atom: may phonic acid, is then reduced with iron powder and hydroreqmre a.h1.gher .temperature for examp 1e 504.00 chloric acid by the Bchamp method. The 4-amino-4'- Where it is desired to replace all of the chlorine atoms (p i b yl i ilb 2.zl di lph i acid 0 1 m the compound of Formula H 18 a pale yellow crystalline product, is isolated by crystalferred to conduct the replacement of the chlorine atoms lization from Water as the Sodium salt in two stages, for example by reacting the compound of 16 Parts of the disodium salt of i 55532 g g z 2 gg gfii fi i f gi benzoyl-amino) -stilbene 2:2-disulphonic acid (83% chlorgle atoms the IHOIECuI g z izf g g 2 pure) are dissolved in 500 parts of water and added slowly I o to a well-stirred solution of 9.25 rns. cyanuric chlorideli ig ggg of a i F? to i" in- 100 parts of toluene, the reactio n mixture being mainformula HX g a g f compfoun I t e tained neutral by the addition of 10% sodium hydroxide L m W may e erent 2 mat of from time to time to neutralize the hydrochloric acid the first 9 for eyampleldlethanolammet to formed and the temperature maintained at 10-15' C plaie thet rgmajmmg chlorine TtOIIAS- Whilst maintaining the reaction mixture neutral with a eve y ace i agtoms sodium hydroxide it is stirred until no more primary 1f d es1red be converted to hydroxy groups. This can con- 50 amino groups canb-e detected (asjudged by the diam vemently be effected by treatment with an equivalent reaction) k l fi 9 Sodlum hydromde Solutlon to hydrolyse Qfi The mixture is raised to 25 C. and 4.65 parts of aniline t E 9 f F added. The reaction mixture is maintained neutral by egogipoun o ormula II may conven cnt lf be the additionof sodium hydroxide solution as before till p p Y treaung thedlsodmm salt of 4-am1n0-4 "(P- the first twochlorine atoms are replaced by aniline and amino-benzoylamino)-stilbene-2:2-disulphonic acid with no more iili can b V H e detected as ud d b th cyanunc chlor1de. The condensation of cyanuric chloti J gs y e dlazo r166 preferably takes Place at acid P and at room t m- The mixture is heated to 40 c. and salted out to obperature, the cyanuric chloride being preferably added tain the om u d R =NHC H d R =C1 Thi to the reaction in solution in an organic solvent, for expound can be used for brightening textiles ample, toluene or acetone; An alkali, e. g. sodium hydroxide' is conveniently added subsequently to bring the reaction mixture to neutral pH before proceeding with The reaction mixture of Example 1 is Slowly heated the other stages of the reaction. Althoughthe product to Without isolation of the Product and Parts may be lsolated at this stage it is preferred to treat the 0f diethanolamine added- The temperature isihengrad- Example 2 produ t without i ol ti b th process d ib d b ually raised to the boiling point and the toluene distilled to yield th new compounds f h present invention, off; The reaction" is assisted as beforeby addition of Th di di s l of 4 i 4' p sodium hydroxide solution. The reaction mixture is then ammo)-stilbene-2:2-disulphonic acid can be readi v obcooled, filterediand Washedon Y g the residue a ran d, f l f 4. i -4' product is obtained in the form'of the sodium salt after 3 111119)-gti]bene 2;2'-di u1 h i i by reduction there filtration and drying, in the form of a light yellow powder of w th iro powder d h d hl i acid, according to which is very suitable due to its fluorescent properties and the B'champ method anditreatrnent of the product with afimity/for cellulose-for brightening and Whitening textile excess sodium. hydr id hil h 4-amino;4'-(p-nitrogoods It is the di-sodium salt of the compoundin which" benzoyl-amino)TstiIbene-Z:'2'-disulphonic' acid used as R is -NHC H and R is -N(CH CH OH) Example 3 16 parts of 4-amino-4'-(p-amino-benzoyl-amino)-stilbene-2:2-disulphonic acid obtained as described in Example 1 is dissolved in 500 parts of water and the solution added, with vigorous agitation, to a suspension of finely divided cyanuric chloride in cold aqueous acetone, prepared by addition of 200 parts of ice to a solution of 9.2 parts of cyanuric chloride in 50 parts of acetone. During the addition of this solution the reaction mixture is maintained at -16" C. The hydrochloric acid produced during the reaction is neutralized by the addition of a dilute solution of sodium hydroxide. The reaction is complete when the mixture no longer gives the usual diazo test for excess amine.

The temperature of the reaction mixture is then raised to 25-30 C. and 3.05 parts of monoethanolamine, dis solved in 10 parts of water, is run in slowly. The hydrochloric acid produced by the reaction is gradually neutralized by the addition of a dilute solution of sodium hydroxide. When the monoethanolamine has completely reacted with the first two chlorine atoms in the two cyanuric chloride molecules, the temperature of the final reaction mixture is raised to 60 C. without isolation of the product and 40 parts of sodium hydroxide solu-.

tion (10%) are added to the suspension. The mixture is slowly raised to the boil and after refluxing for 1 hour to ensure completion of hyldrolysis of the remaining two chlorine atoms to hydroxyl groups the acetone is distilled off. The product which precipitates on cooling, is isolated by filtering and on drying gives a bright yellow powder, which is again fluorescent and has good afiinity for cellulose. This is the sodium salt of the compound in which R is -OH and R is NHCH CH OH.

Example 5 32 parts of 4-amino-4-(p-amino-benzoyl-amino)-stilbene-2:2-disulphonic acid (83% pure) are condensed with 18.5 parts of cyanuric chloride as described in Example l.

The compound so obtained acted first with 21.2 parts of the sodium salt of metanilic acid at 25-35 C. and then with 9.3 parts of aniline at 50-100 C. The final product is isolated as the sodium salt by salting out. A product is obtained in which and R =NHC H which product gives a solution which exhibits bluish green fluorescence and is substantive to cellulose. l

is not isolated and is re- Example 6 When the compound obtained by condensing 16 parts 6 Example 7 When in Example 2 aniline is replaced by p-anisidine (6.15 parts) a product is obtained in which and R =-N(CH CH 0H) which is very similar in properties to the product of Example 2.

Example 8 32 parts of 4-amino-4-(p-amino-benzoyl-amino)-stilbene-2:2-disulphonic acid (disodium salt) are condensed as before with 18.5 parts of cyanuric chloride. The intermediate compound is next condensed first with 2 mols. of diethanolamine and next with a further 2 mols. of diethanolamine. The product in which CHzCHzOH CHnCHgOH and.

R =-N \CHZCHQOH is obtained by salting out and is An aqueous solution blue fluorescence.

quite soluble in water. of the product exhibits a greenish Example 9 When the product obtained in Example 1 is refluxed with an excess of ammonia (12 parts, sp. gr. 0.88) for about 4 hours 'and allowed to cool and acidified, the free acid of the compound R =NHC H and R ==NH is obtained. This compound is fluorescent in solution and is substantive to cellulose.

Example 10 When the compound obtained in Example 1 is refluxed with 10 parts of monomethylamine (40%) and the product salted out, a compound in which R NHC H and R NHCH is obtained. This compound has properties very similar to those obtained in Examples 2 and 6.

Example 11 and R =-NHCH CH OH is isolated by acidification,

filtration, washing and drying. It is a greenish yellow product which gives a slightly greener shade of fluorescence on cotton than the other compounds mentioned above.

Example 12 32 parts of 4-amino-4'-(p-amino-benzoyl-amino)- stilbene-2 :2-disulphonic acid were condensed with 18.5 parts cyanuric chloride 'and the compound obtained then condensed with 10.7 parts of methyl aniline and 10.5 parts diethanolamine in the usual manner. The -resulting product is isolated as the sodium salt and has excellent brightening properties on cellulose when applied from a detergent or neutral bath. l

H5 8. A compound as defined. inrclaim 1 in which R is R1'=. ;N' f aHI and a andRzis -NHC l-l and the sodium salts thereof;

R2 N/CITIHCHZOH 9. Awc'ompound as defined in claim 1 in which R is cr-ncmon CHWHQ 10 Example 13 z A piece of'white cotton poplin (bleached) istreated' r v in a bath with .02 of the compound obtained accordand 5 NHC6H5 and the 9 'F P 1 ing to Example Z-in the presence of the 5% sodium sul- 15 Acompound as'defined m chum 1 m Winch R phate' (Glaube rs salt) for half-an-hour' at 60 C. in a v dye bath. After rinsing and drying the material ap pears considerably whiter and. brighter than the untreated material. The material has av faintly greenish fluorescence. 20, CHzOH zOH We claim: 1. As an optical whitening and brightening agent, the compound having in its free acid form the formula CHYCHWH R1 v R1 l a l 3 -0 c-NH-C -0H=0H DIEGO-ONH-i) 0-R= N N SOaH SOaH where R is selected from the group consisting of rnorand the sodium salts thereof. pholino and- 11. Acompound asdefined in claim 1 in whichR is /GH2CH2OH OHZCHQOH inwhich X and Y are selected from the group consisting and R is of hydrogen, lower alkyl, lower hydroxy alkyl, phenyl, CHQCHZOH- methoxy phenyl, tolyl- N so H 3 ornomon NH- and the sodium salts thereof.

12. A compound as defined in claim 1 in which R is.

and ''NHC H5 and R -is -NH and the sodium salts thereof.

N 13. A- compound as defined in claim- 1 in which R 'is -NHC H and R is NHCH and the sodium salts thereof.-'

\ 14. A-compound'as defined in claim-1 in which R is NHCH" GH OH- and R is V and R is selectedfrom the group consistingof R1, chloro N and hydroxyl. 552

2. The alkali-metal salts of the compounds defined in claim 1.

3. The sodium salts of the compounds defined in claim 1. a

4. A compound as defined in claim 1 in which R the Sodium Salts therreofl is -NHC H and R is a chlorine atom and the sodium A compound as defined Claim 1 in Which R1 is salts thereof.

5. A compound" as defined in claim 1 in which R is 5 1 -NHCgH and R is CIlzCHzOH CeHr and. R is V V v CHzCHaOH CHgCHzOH and the sodium salts thereof.

6. A compound as; defined in claim 1 inwhich R? is: 701 -IlI-IC I-I and. R3 is -NHC H and. the sodium'salts" OHZOHZOH thereof.

, 7 Acompound as defined in claim 1' in which R is and the sodium salts thereof; H NHCH CH OH and R isa hydroxyl. group and the so 16. A. process for: improving thewhiteness and brightdium salts thereof. ness of cellulosic': textiles: comprising treating; said textiles 9 10 with the compound having in its free acid form the formula R m l l 11 -4 (L-NH cn=o1{- NRCO-O-NH- ll-R N 0.11 soar where R is selected from the group consisting of morand pholino and N x 0 on.

Y and R is selected from the group consisting of R, chloro and hydrcxyl. in which X and Y are selected from the group consisting 2o of hydrogen, lower alkyl, lower hydroxy alkyl, phenyl, References Cited file of this Patent methoxy phenyl, tolyl UNITED STATES PATENTS 2,694,064 Hausermann Nov. 9, 1954 50']! 2,778,827 Ackermann Ian. 22, 1957 Q FOREIGN PATENTS 973,938 France Feb. 16, 1951 

16. A PROCESS FOR IMPROVING THE WHITENESS AND BRIGHTNESS OF CELLULOSIC TEXTILES COMPRISING TREATING SAID TEXTILES WITH THE COMPOUND HAVING IN ITS FREE ACID FORM THE FORMULA 